Lithographic plate.



S. A. NEIDICH.

LITHOGRAPHIC PLATE.

APPLICATION FILED AuG.22.1914.

l .,20337@ Patentea Nov. 7, 1916.

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UNITED sra'rns PATENT onirica.

SAMUEL-A. NEIDICH, OF EDGEWATER PARK, NEW JERSEY, ASSIGN OR TO THE AMERI- CAN MULTIGRAPH COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

LITHO GRAPHIC PLATE.

Specification of Letters Patent.

Patented Nov. 7, 1916.

Application led August 22, 1914. Serial No. 858,012.

To all whom t may concern.'

.Be 1t known that I, SAMUEL A. NEIDICH, a citizen of the United States, 'residing at Edgewater Park, in the county of Burlington and State of New Jersey, have invented a certain new and useful Improvement in Lithographie Plates, of which the following is a full, clear, and exact description, reference being had to the accompanying' drawmgs.

plates of such a character that they may have the work or image rmly aiiiXed thereto by a minimum amount of labor and skill, and, when so prepared, will be very efficient and extremely durable in service. My plate, before the work is applied, has its entire face ink-resisting, -when moist, but adapted to hold at any desired place an adhering.

ink-receiving substance.. The eXtreme desirability of such a plate will be best understood'by contrast with the troublesome working requirements of ordinary plates.

In the ordinary processes of preparing metal lithographie plates for printing, a grained plate has the work or image applied direct `to it in some greasy medium and thereafter the balance of the plate is etched and gummed to make it ink-resisting when moist. In such -old processes it is very important that no grease be present on the grained plate where printing is not desired, and that the plate be kept free from oxidization, and great skill is required, as well as considerable time, in accomplishing the etching. Inasmuch as the etching operation tends to remove the work, the usual method has been to partially etch the plate and thereafter strengthen the Work and then further etch the plate and further strengthen the work, if necessary. These successive operations require great skill and caution, lest thework be partially removed by the' etching substances. There is great liability of spoiling the plate during this process, for, if the etching removes the least part of the work, the plate is ruined, or is only preserved by tedious subsequent operations.

Unless the operation is carried out with the greatest possible care, the plate lacks durability, as the image is liable to become partially removed during the operation of the` printing. Furthermore, the work asordi-l narily prepared upon the plate, is soluble in This invention relates to lithographic all the ordinary solvents for ink, and, should ink accidentally be permitted to dry on the face of the plate, it is diiicult of removal l the usual gum arabic solution is used with the etching of the plate and to the gummed and dried plate is applied the image by means of a hard emulsiied wax and a substance like bichromate of ammonium, which, when heated, coact With the gum and produce a dry compound of wax and bichromated gum carrying the image. The emulsiied wax may be carried eitherl by the image-applying solution or may be incorporated with the gum of the plate,-in the latter instance, the wax, at the places. Where there is no image, washing off with the gum arabic.

It will be seen that in each instance the plate is etched over its entire face preliminary to the work-being applied, and thereafter the work is applied, as'desired, on an etched surface. By such a process I do *away with the element of skill in the etching operation.y as 'I am not hampered by the presence of any work on .the plate. I very materially-shorten the time required, since lA can use the strongest etching solution and accomplish it at one time instead of by several successive operations. The plate is not liable to be spoiled by reason of ink inadvertently drying on the surface, for at any time such ink ma)y be dissolved off without affecting the work. Finally, my plate is more permanent, both in its ink-carrying and ink-resisting properties, Y.

Inasmuch as thel etchingI of my plate is entirely independent of the character of the work to be produced, it is possible to performthe etching as a manufacturing operatiorn'in conjunction with the vgraining of the plate, and to supply to users readyetched plates having wonderfully greater keeping qualities than the usual grained plates, as well as free from the possibility of damage from accidental grease deposits or from oxidization. Chemical manipulation of the plate-by the users-is thereupon eliminated, as he is only required to apply the image to the plate and secure it by heating.

The present application relates to the preetclied plate itself, which may be used in carrying out lithographie operations, of which these described are examples. This plate may be briefly summarized as .a new article of manufacture, comprising a plate chemically prepared for lithographie purposes and capable, when moist, of resisting ink over its entire surface and capable of having an ink-receiving image adhere to it, whereby it becomes an effective lithographie printing plate.

The plate of this invention may be of any suitable metal. I have found zinc well adapted for the purposes. The zinc plate is first mechanically grained in the ordinary manner and is then etched over its entire face before yany work is applied. This etching may be accomplished by usual etching solutions, though I prefer to .use a strong solution to save time.

After my plate is etched it may be preserved indefnitely; it does not deteriorate in use and is not liable to be spoiled by greasy thumb marks, etc. If the plate is intended for use according to the process of my application No. 856,201 wherein a waxy image is applied to the plate directly by heat, the plate, as a stock article, needs no further treatment. If, however, I wish to produce a plate adapted for conveniently` carrying out the process of my application No. 856,202, I employ, with the etching solution, the usual gum arabic solution, so that the plate is not only pre'e'tched over its entire face, but is gummed as well. In one methody of carrying out the process of the latter application, I incorporate with the gum arabic solution emulsified carnauba wax, instead of using such emulsion in the work solution itself. Accordingly, the present invention includes a grained pretched plate; second, such a plate guinmed over its face; and third, such a plate gummed and carrying emulsified wax.

My plate is illustrated diagrammatically in the drawings hereof, in which- Figure 1 is a vertical section through the grained and etched plate on a very much enlarged scale. For graphic representation, the etching is shown as surmounting the grain, though, in actual practice itl is incoi'porated with it. Fig. 2 shows the 4plate of Fig. 1 with a Sui-mounting coat of gum. Fig. 3 shows the plate with an image applied above the gum. Fig. 4 is a plan of the plate shown in Fig. 3.

drawings is prepared by taking a plate of zinc, aluminum or other suitable metal,

graining it, as in the ordinary lithographie process, and etching the entire face thereof very completely, so as to make a thoroughly ink-resisting surface. For these purposes I may use any of thel well-known etching conipounds, preferably a comparatively strong Y compound. For producing the plate shown in Figs. 2 and 3. of the drawings, in addition to etching the plate, I gum it and drum the gum. Where it is desired to incorporate in the gum an emulsified hard wax, as above referred to, this may be conveniently accomplished by mixing with vthe gum arabic solution an emulsion of carnauba with water of such proportions that the final mixture will contain approximately equal quantities of solid gum arabic and solid cai'nauba wax, the latter in suspension. The emulsilied carnauba may be obtained on the market as an emulsion, or may be emulsiicd by employing amidduron or steal-amid (i. e., the amid of stearic acid, CNHSSCONILQ which is on the market for such purposes.

Whether my pretched plate is used without the gum solution and has the waximage applied thereto by heat, or is used with. the gum solution and has the image applied in the form of a bichromate solution with wax and thereafter heated, or is :used with gum and wax incorporated witha plate and has the image applied simply as a bichroinate solution affixed by heatin any case, the plate is characterized by having its entire face etched previous to the application of any work to the plate.

Having thus described `my invention, what I claim is:

1. As a new article of manufacture, a inetallic plate adapted for lithographie purposes and capableI when moist of resisting ink over its entire face sufliciently for lithographic printing without subsequent chemical treatment and capable of having an inkcarrying image affixed vfirmly to it.

2. As a new article of manufacture, a inctallic lithographie plate etched over its entire face suflieiently to be workable when moist as an ink-repellent surface without further chemical treatment and adapted to receive a design thereon.

3. As a new article of manufacture. a inci tallic lithographie plate grained and etched `over its entire face, to be ink-resisting suftallic lithographie plate etched to be inkresisting sufficiently for lithographie printing when moist, and gummed over its entire face.

5. As a new article of manufacture, a metallic lithographie plate grained, etched to be ink-resisting sufficiently for lithographie.

8. As a new article of manufacture, a lithographie plate grained, etched and gummed over its entire face, the gum containing emulsiied wax.

9. As a new article of manufacture, a plate adapted for lithographie purposes consisting of a metal plate etched over its entire face, and gummed over its entire face, the gum containing emulsified earnauba waX.

10. As a new article of manufacture,l a plate adapted for lithographie purposes con# sisting of a metal plate grained over its entire face and etched over the entire face, and gummed over the entire face with a solution of gum arabic containing emulsified earnauba wax.

In testimony whereof, I hereunto aflix my signature in the presence of two Witnesses.

SAMUEL A. NEIDICH.

Witnesses:

W. JoNsE HUGHES, JOHN W. DAVIS. 

